Skiving block for mitigating protruding defects from magnetic tape recording media

ABSTRACT

An apparatus according to one embodiment includes a block having multiple skiving edges along a tape bearing surface thereof, and a guide mechanism configured to set a wrap angle of a tape approaching the skiving edge. A drive mechanism is configured to cause the tape to move over the block. The block has no transducer coupled directly thereto. A computer-implemented method according to one embodiment includes causing a magnetic recording tape to pass over a block having a skiving edge at a wrap angle of at least one degree for burnishing the tape, wherein the block has an average hardness of at least about 9 Mohs.

BACKGROUND

The present invention relates to data storage systems, and moreparticularly, this invention relates to mitigating defect abrasivity ofmagnetic tape recording media.

In magnetic storage systems, magnetic transducers read data from andwrite data onto magnetic recording media. Data is written on themagnetic recording media by moving a magnetic recording transducer to aposition over the media where the data is to be stored. The magneticrecording transducer then generates a magnetic field, which encodes thedata into the magnetic media. Data is read from the media by similarlypositioning the magnetic read transducer and then sensing the magneticfield of the magnetic media. Read and write operations may beindependently synchronized with the movement of the media to ensure thatthe data can be read from and written to the desired location on themedia.

An important and continuing goal in the data storage industry is that ofincreasing the density of data stored on a medium. For tape storagesystems, that goal has led to increasing the track and linear bitdensity on recording tape, and decreasing the thickness of the magnetictape medium. However, the development of small footprint, higherperformance tape drive systems has created various problems in thedesign of a tape head assembly for use in such systems.

In a tape drive system, the drive moves the magnetic tape over thesurface of the tape head at high speed. Usually the tape head isdesigned to minimize the spacing between the head and the tape. Thespacing between the magnetic head and the magnetic tape is crucial andso goals in these systems are to have the recording gaps of thetransducers, which are the source of the magnetic recording flux in nearcontact with the tape to effect writing sharp transitions, and to havethe read elements in near contact with the tape to provide effectivecoupling of the magnetic field from the tape to the read elements.

SUMMARY

An apparatus according to one embodiment includes a block havingmultiple skiving edges along a tape bearing surface thereof, and a guidemechanism configured to set a wrap angle of a tape approaching theskiving edge. A drive mechanism is configured to cause the tape to moveover the block. The block has no transducer coupled directly thereto.

A computer-implemented method according to one embodiment includescausing a magnetic recording tape to pass over a block having a skivingedge at a wrap angle of at least one degree for burnishing the tape,wherein the block has an average hardness of at least about 9 Mohs.

A computer program product for burnishing a magnetic recording tape,according to one embodiment, includes a computer readable storage mediumhaving program instructions embodied therewith, wherein the computerreadable storage medium is not a transitory signal per se, the programinstructions executable by a processing circuit to cause the processingcircuit to perform the foregoing method.

Any of these embodiments may be implemented in a magnetic data storagesystem such as a tape drive system, which may include a magnetic head, adrive mechanism for passing a magnetic medium (e.g., recording tape)over the magnetic head, and a controller electrically coupled to themagnetic head.

Other aspects and embodiments of the present invention will becomeapparent from the following detailed description, which, when taken inconjunction with the drawings, illustrate by way of example theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic diagram of a simplified tape drive systemaccording to one embodiment.

FIG. 1B is a schematic diagram of a tape cartridge according to oneembodiment.

FIG. 2 illustrates a side view of a flat-lapped, bi-directional,two-module magnetic tape head according to one embodiment.

FIG. 2A is a tape bearing surface view taken from Line 2A of FIG. 2.

FIG. 2B is a detailed view taken from Circle 2B of FIG. 2A.

FIG. 2C is a detailed view of a partial tape bearing surface of a pairof modules.

FIG. 3 is a partial tape bearing surface view of a magnetic head havinga write-read-write configuration.

FIG. 4 is a partial tape bearing surface view of a magnetic head havinga read-write-read configuration.

FIG. 5 is a side view of a magnetic tape head with three modulesaccording to one embodiment where the modules all generally lie alongabout parallel planes.

FIG. 6 is a side view of a magnetic tape head with three modules in atangent (angled) configuration.

FIG. 7 is a side view of a magnetic tape head with three modules in anoverwrap configuration.

FIG. 8 is a perspective view of a pair of skiving blocks mounted on asimulated head assembly, according to one embodiment.

FIG. 9 is a schematic diagram of a simplified tape drive system with askiving block, according to one embodiment.

FIG. 10 is a schematic diagram of a simplified tape drive system with askiving block, according to one embodiment.

FIG. 11A is a schematic diagram of a simplified tape drive system with askiving block in a retracted position, according to one embodiment.

FIG. 11B is a schematic diagram of the simplified tape drive system ofFIG. 11A with a skiving block in a burnishing position, according to oneembodiment.

FIG. 11C is a schematic diagram of a simplified tape drive system ofFIGS. 11A-11B with a skiving block in a lifting position, according toone embodiment.

FIG. 12 is a schematic diagram of a simplified tape drive system withtwo skiving blocks, according to one embodiment.

DETAILED DESCRIPTION

The following description is made for the purpose of illustrating thegeneral principles of the present invention and is not meant to limitthe inventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.

Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

It must also be noted that, as used in the specification and theappended claims, the singular forms “a,” “an” and “the” include pluralreferents unless otherwise specified.

The following description discloses several preferred embodiments ofmagnetic storage systems, as well as operation and/or component partsthereof.

In one general embodiment, an apparatus includes a block having multipleskiving edges along a tape bearing surface thereof, and a guidemechanism configured to set a wrap angle of a tape approaching theskiving edge. A drive mechanism is configured to cause the tape to moveover the block. The block has no transducer coupled directly thereto.

In one general embodiment, a computer-implemented method includescausing a magnetic recording tape to pass over a block having a skivingedge at a wrap angle of at least one degree for burnishing the tape,wherein the block has an average hardness of at least about 9 Mohs.

In one general embodiment, a computer program product for burnishing amagnetic recording tape includes a computer readable storage mediumhaving program instructions embodied therewith, wherein the computerreadable storage medium is not a transitory signal per se, the programinstructions executable by a processing circuit to cause the processingcircuit to perform the foregoing method.

FIG. 1A illustrates a simplified tape drive 100 of a tape-based datastorage system, which may be employed in the context of the presentinvention. While one specific implementation of a tape drive is shown inFIG. 1A, it should be noted that the embodiments described herein may beimplemented in the context of any type of tape drive system.

As shown, a tape supply cartridge 120 and a take-up reel 121 areprovided to support a tape 122. One or more of the reels may form partof a removable cartridge and are not necessarily part of the system 100.The tape drive, such as that illustrated in FIG. 1A, may further includedrive motor(s) to drive the tape supply cartridge 120 and the take-upreel 121 to move the tape 122 over a tape head 126 of any type. Suchhead may include an array of readers, writers, or both.

Guides 125 guide the tape 122 across the tape head 126 at a desired wrapangle. Such tape head 126 is in turn coupled to a controller 128 via acable 130. The controller 128, may be or include a processor and/or anylogic for controlling any subsystem of the drive 100. For example, thecontroller 128 typically controls head functions such as servofollowing, data writing, data reading, etc. The controller 128 mayinclude at least one servo channel and at least one data channel, eachof which include data flow processing logic configured to process and/orstore information to be written to and/or read from the tape 122. Thecontroller 128 may operate under logic known in the art, as well as anylogic disclosed herein, and thus may be considered as a processor forany of the descriptions of tape drives included herein, in variousembodiments. The controller 128 may be coupled to a memory 136 of anyknown type, which may store instructions executable by the controller128. Moreover, the controller 128 may be configured and/or programmableto perform or control some or all of the methodology presented herein.Thus, the controller 128 may be considered to be configured to performvarious operations by way of logic programmed into one or more chips,modules, and/or blocks; software, firmware, and/or other instructionsbeing available to one or more processors; etc., and combinationsthereof.

The cable 130 may include read/write circuits to transmit data to thehead 126 to be recorded on the tape 122 and to receive data read by thehead 126 from the tape 122. An actuator 132 controls position of thehead 126 relative to the tape 122.

An interface 134 may also be provided for communication between the tapedrive 100 and a host (internal or external) to send and receive the dataand for controlling the operation of the tape drive 100 andcommunicating the status of the tape drive 100 to the host, all as willbe understood by those of skill in the art.

FIG. 1B illustrates an exemplary tape cartridge 150 according to oneembodiment. Such tape cartridge 150 may be used with a system such asthat shown in FIG. 1A. As shown, the tape cartridge 150 includes ahousing 152, a tape 122 in the housing 152, and a nonvolatile memory 156coupled to the housing 152. In some approaches, the nonvolatile memory156 may be embedded inside the housing 152, as shown in FIG. 1B. In moreapproaches, the nonvolatile memory 156 may be attached to the inside oroutside of the housing 152 without modification of the housing 152. Forexample, the nonvolatile memory may be embedded in a self-adhesive label154. In one preferred embodiment, the nonvolatile memory 156 may be aFlash memory device, ROM device, etc., embedded into or coupled to theinside or outside of the tape cartridge 150. The nonvolatile memory isaccessible by the tape drive and the tape operating software (the driversoftware), and/or other device.

By way of example, FIG. 2 illustrates a side view of a flat-lapped,bi-directional, two-module magnetic tape head 200 which may beimplemented in the context of the present invention. As shown, the headincludes a pair of bases 202, each equipped with a module 204, and fixedat a small angle α with respect to each other. The bases may be“U-beams” that are adhesively coupled together. Each module 204 includesa substrate 204A and a closure 204B with a thin film portion, commonlyreferred to as a “gap” in which the readers and/or writers 206 areformed. In use, a tape 208 is moved over the modules 204 along a media(tape) bearing surface 209 in the manner shown for reading and writingdata on the tape 208 using the readers and writers. The wrap angle θ ofthe tape 208 at edges going onto and exiting the flat media supportsurfaces 209 are usually between about 0.1 degree and about 3 degrees.

The substrates 204A are typically constructed of a wear resistantmaterial, such as a ceramic. The closures 204B may be made of the sameor similar ceramic as the substrates 204A.

The readers and writers may be arranged in a piggyback or mergedconfiguration. An illustrative piggybacked configuration comprises a(magnetically inductive) writer transducer on top of (or below) a(magnetically shielded) reader transducer (e.g., a magnetoresistivereader, etc.), wherein the poles of the writer and the shields of thereader are generally separated. An illustrative merged configurationcomprises one reader shield in the same physical layer as one writerpole (hence, “merged”). The readers and writers may also be arranged inan interleaved configuration. Alternatively, each array of channels maybe readers or writers only. Any of these arrays may contain one or moreservo track readers for reading servo data on the medium.

FIG. 2A illustrates the tape bearing surface 209 of one of the modules204 taken from Line 2A of FIG. 2. A representative tape 208 is shown indashed lines. The module 204 is preferably long enough to be able tosupport the tape as the head steps between data bands.

In this example, the tape 208 includes 4 to 32 data bands, e.g., with 16data bands and 17 servo tracks 210, as shown in FIG. 2A on a one-halfinch wide tape 208. The data bands are defined between servo tracks 210.Each data band may include a number of data tracks, for example 1024data tracks (not shown). During read/write operations, the readersand/or writers 206 are positioned to specific track positions within oneof the data bands. Outer readers, sometimes called servo readers, readthe servo tracks 210. The servo signals are in turn used to keep thereaders and/or writers 206 aligned with a particular set of tracksduring the read/write operations.

FIG. 2B depicts a plurality of readers and/or writers 206 formed in agap 218 on the module 204 in Circle 2B of FIG. 2A. As shown, the arrayof readers and writers 206 includes, for example, 16 writers 214, 16readers 216 and two servo readers 212, though the number of elements mayvary. Illustrative embodiments include 8, 16, 32, 40, and 64 activereaders and/or writers 206 per array, and alternatively interleaveddesigns having odd numbers of reader or writers such as 17, 25, 33, etc.An illustrative embodiment includes 32 readers per array and/or 32writers per array, where the actual number of transducer elements couldbe greater, e.g., 33, 34, etc. This allows the tape to travel moreslowly, thereby reducing speed-induced tracking and mechanicaldifficulties and/or execute fewer “wraps” to fill or read the tape.While the readers and writers may be arranged in a piggybackconfiguration as shown in FIG. 2B, the readers 216 and writers 214 mayalso be arranged in an interleaved configuration. Alternatively, eacharray of readers and/or writers 206 may be readers or writers only, andthe arrays may contain one or more servo readers 212. As noted byconsidering FIGS. 2 and 2A-B together, each module 204 may include acomplementary set of readers and/or writers 206 for such things asbi-directional reading and writing, read-while-write capability,backward compatibility, etc.

FIG. 2C shows a partial tape bearing surface view of complementarymodules of a magnetic tape head 200 according to one embodiment. In thisembodiment, each module has a plurality of read/write (R/W) pairs in apiggyback configuration formed on a common substrate 204A and anoptional electrically insulative layer 236. The writers, exemplified bythe write transducer 214 and the readers, exemplified by the readtransducer 216, are aligned parallel to an intended direction of travelof a tape medium thereacross to form an R/W pair, exemplified by the R/Wpair 222. Note that the intended direction of tape travel is sometimesreferred to herein as the direction of tape travel, and such terms maybe used interchangeably. Such direction of tape travel may be inferredfrom the design of the system, e.g., by examining the guides; observingthe actual direction of tape travel relative to the reference point;etc. Moreover, in a system operable for bi-direction reading and/orwriting, the direction of tape travel in both directions is typicallyparallel and thus both directions may be considered equivalent to eachother.

Several R/W pairs 222 may be present, such as 8, 16, 32 pairs, etc. TheR/W pairs 222 as shown are linearly aligned in a direction generallyperpendicular to a direction of tape travel thereacross. However, thepairs may also be aligned diagonally, etc. Servo readers 212 arepositioned on the outside of the array of R/W pairs, the function ofwhich is well known.

Generally, the magnetic tape medium moves in either a forward or reversedirection as indicated by arrow 220. The magnetic tape medium and headassembly 200 operate in a transducing relationship in the mannerwell-known in the art. The piggybacked MR head assembly 200 includes twothin-film modules 224 and 226 of generally identical construction.

Modules 224 and 226 are joined together with a space present betweenclosures 204B thereof (partially shown) to form a single physical unitto provide read-while-write capability by activating the writer of theleading module and reader of the trailing module aligned with the writerof the leading module parallel to the direction of tape travel relativethereto. When a module 224, 226 of a piggyback head 200 is constructed,layers are formed in the gap 218 created above an electricallyconductive substrate 204A (partially shown), e.g., of AlTiC, ingenerally the following order for the R/W pairs 222: an insulating layer236, a first shield 232 typically of an iron alloy such as NiFe (−),cobalt zirconium tantalum (CZT) or Al—Fe—Si (Sendust), a sensor 234 forsensing a data track on a magnetic medium, a second shield 238 typicallyof a nickel-iron alloy (e.g., ˜80/20 at % NiFe, also known aspermalloy), first and second writer pole tips 228, 230, and a coil (notshown). The sensor may be of any known type, including those based onMR, GMR, AMR, tunneling magnetoresistance (TMR), etc.

The first and second writer poles 228, 230 may be fabricated from highmagnetic moment materials such as ˜45/55 NiFe. Note that these materialsare provided by way of example only, and other materials may be used.Additional layers such as insulation between the shields and/or poletips and an insulation layer surrounding the sensor may be present.Illustrative materials for the insulation include alumina and otheroxides, insulative polymers, etc.

The configuration of the tape head 126 according to one embodimentincludes multiple modules, preferably three or more. In awrite-read-write (W-R-W) head, outer modules for writing flank one ormore inner modules for reading. Referring to FIG. 3, depicting a W-R-Wconfiguration, the outer modules 252, 256 each include one or morearrays of writers 260. The inner module 254 of FIG. 3 includes one ormore arrays of readers 258 in a similar configuration. Variations of amulti-module head include a R-W-R head (FIG. 4), a R-R-W head, a W-W-Rhead, etc. In yet other variations, one or more of the modules may haveread/write pairs of transducers. Moreover, more than three modules maybe present. In further approaches, two outer modules may flank two ormore inner modules, e.g., in a W-R-R-W, a R-W-W-R arrangement, etc. Forsimplicity, a W-R-W head is used primarily herein to exemplifyembodiments of the present invention. One skilled in the art apprisedwith the teachings herein will appreciate how permutations of thepresent invention would apply to configurations other than a W-R-Wconfiguration.

FIG. 5 illustrates a magnetic head 126 according to one embodiment ofthe present invention that includes first, second and third modules 302,304, 306 each having a tape bearing surface 308, 310, 312 respectively,which may be flat, contoured, etc. Note that while the term “tapebearing surface” appears to imply that the surface facing the tape 315is in physical contact with the tape bearing surface, this is notnecessarily the case. Rather, only a portion of the tape may be incontact with the tape bearing surface, constantly or intermittently,with other portions of the tape riding (or “flying”) above the tapebearing surface on a layer of air, sometimes referred to as an “airbearing”. The first module 302 will be referred to as the “leading”module as it is the first module encountered by the tape in a threemodule design for tape moving in the indicated direction. The thirdmodule 306 will be referred to as the “trailing” module. The trailingmodule follows the middle module and is the last module seen by the tapein a three module design. The leading and trailing modules 302, 306 arereferred to collectively as outer modules. Also note that the outermodules 302, 306 will alternate as leading modules, depending on thedirection of travel of the tape 315.

In one embodiment, the tape bearing surfaces 308, 310, 312 of the first,second and third modules 302, 304, 306 lie on about parallel planes(which is meant to include parallel and nearly parallel planes, e.g.,between parallel and tangential as in FIG. 6), and the tape bearingsurface 310 of the second module 304 is above the tape bearing surfaces308, 312 of the first and third modules 302, 306. As described below,this has the effect of creating the desired wrap angle α₂ of the taperelative to the tape bearing surface 310 of the second module 304.

Where the tape bearing surfaces 308, 310, 312 lie along parallel ornearly parallel yet offset planes, intuitively, the tape should peel offof the tape bearing surface 308 of the leading module 302. However, thevacuum created by the skiving edge 318 of the leading module 302 hasbeen found by experimentation to be sufficient to keep the tape adheredto the tape bearing surface 308 of the leading module 302. The trailingedge 320 of the leading module 302 (the end from which the tape leavesthe leading module 302) is the approximate reference point which definesthe wrap angle α₂ over the tape bearing surface 310 of the second module304. The tape stays in close proximity to the tape bearing surface untilclose to the trailing edge 320 of the leading module 302. Accordingly,read and/or write elements 322 may be located near the trailing edges ofthe outer modules 302, 306. These embodiments are particularly adaptedfor write-read-write applications.

A benefit of this and other embodiments described herein is that,because the outer modules 302, 306 are fixed at a determined offset fromthe second module 304, the inner wrap angle α₂ is fixed when the modules302, 304, 306 are coupled together or are otherwise fixed into a head.The inner wrap angle α₂ is approximately tan⁻¹(δ/W) where δ is theheight difference between the planes of the tape bearing surfaces 308,310 and W is the width between the opposing ends of the tape bearingsurfaces 308, 310. An illustrative inner wrap angle α₂ is in a range ofabout 0.3° to about 1.1°, though can be any angle required by thedesign.

Beneficially, the inner wrap angle α₂ on the side of the module 304receiving the tape (leading edge) will be larger than the inner wrapangle α₃ on the trailing edge, as the tape 315 rides above the trailingmodule 306. This difference is generally beneficial as a smaller α₃tends to oppose what has heretofore been a steeper exiting effectivewrap angle.

Note that the tape bearing surfaces 308, 312 of the outer modules 302,306 are positioned to achieve a negative wrap angle at the trailing edge320 of the leading module 302. This is generally beneficial in helpingto reduce friction due to contact with the trailing edge 320, providedthat proper consideration is given to the location of the crowbar regionthat forms in the tape where it peels off the head. This negative wrapangle also reduces flutter and scrubbing damage to the elements on theleading module 302. Further, at the trailing module 306, the tape 315flies over the tape bearing surface 312 so there is virtually no wear onthe elements when tape is moving in this direction. Particularly, thetape 315 entrains air and so will not significantly ride on the tapebearing surface 312 of the third module 306 (some contact may occur).This is permissible, because the leading module 302 is writing while thetrailing module 306 is idle.

Writing and reading functions are performed by different modules at anygiven time. In one embodiment, the second module 304 includes aplurality of data and optional servo readers 331 and no writers. Thefirst and third modules 302, 306 include a plurality of writers 322 andno data readers, with the exception that the outer modules 302, 306 mayinclude optional servo readers. The servo readers may be used toposition the head during reading and/or writing operations. The servoreader(s) on each module are typically located towards the end of thearray of readers or writers.

By having only readers or side by side writers and servo readers in thegap between the substrate and closure, the gap length can besubstantially reduced. Typical heads have piggybacked readers andwriters, where the writer is formed above each reader. A typical gap is20-35 microns. However, irregularities on the tape may tend to droopinto the gap and create gap erosion. Thus, the smaller the gap is thebetter. The smaller gap enabled herein exhibits fewer wear relatedproblems.

In some embodiments, the second module 304 has a closure, while thefirst and third modules 302, 306 do not have a closure. Where there isno closure, preferably a hard coating is added to the module. Onepreferred coating is diamond-like carbon (DLC).

In the embodiment shown in FIG. 5, the first, second, and third modules302, 304, 306 each have a closure 332, 334, 336, which extends the tapebearing surface of the associated module, thereby effectivelypositioning the read/write elements away from the edge of the tapebearing surface. The closure 332 on the second module 304 can be aceramic closure of a type typically found on tape heads. The closures334, 336 of the first and third modules 302, 306, however, may beshorter than the closure 332 of the second module 304 as measuredparallel to a direction of tape travel over the respective module. Thisenables positioning the modules closer together. One way to produceshorter closures 334, 336 is to lap the standard ceramic closures of thesecond module 304 an additional amount. Another way is to plate ordeposit thin film closures above the elements during thin filmprocessing. For example, a thin film closure of a hard material such asSendust or nickel-iron alloy (e.g., 45/55) can be formed on the module.

With reduced-thickness ceramic or thin film closures 334, 336 or noclosures on the outer modules 302, 306, the write-to-read gap spacingcan be reduced to less than about 1 mm, e.g., about 0.75 mm, or 50% lessthan commonly-used LTO tape head spacing. The open space between themodules 302, 304, 306 can still be set to approximately 0.5 to 0.6 mm,which in some embodiments is ideal for stabilizing tape motion over thesecond module 304.

Depending on tape tension and stiffness, it may be desirable to anglethe tape bearing surfaces of the outer modules relative to the tapebearing surface of the second module. FIG. 6 illustrates an embodimentwhere the modules 302, 304, 306 are in a tangent or nearly tangent(angled) configuration. Particularly, the tape bearing surfaces of theouter modules 302, 306 are about parallel to the tape at the desiredwrap angle α₂ of the second module 304. In other words, the planes ofthe tape bearing surfaces 308, 312 of the outer modules 302, 306 areoriented at about the desired wrap angle α₂ of the tape 315 relative tothe second module 304. The tape will also pop off of the trailing module306 in this embodiment, thereby reducing wear on the elements in thetrailing module 306. These embodiments are particularly useful forwrite-read-write applications. Additional aspects of these embodimentsare similar to those given above.

Typically, the tape wrap angles may be set about midway between theembodiments shown in FIGS. 5 and 6.

FIG. 7 illustrates an embodiment where the modules 302, 304, 306 are inan overwrap configuration. Particularly, the tape bearing surfaces 308,312 of the outer modules 302, 306 are angled slightly more than the tape315 when set at the desired wrap angle α₂ relative to the second module304. In this embodiment, the tape does not pop off of the trailingmodule, allowing it to be used for writing or reading. Accordingly, theleading and middle modules can both perform reading and/or writingfunctions while the trailing module can read any just-written data.Thus, these embodiments are preferred for write-read-write,read-write-read, and write-write-read applications. In the latterembodiments, closures should be wider than the tape canopies forensuring read capability. The wider closures may require a widergap-to-gap separation. Therefore a preferred embodiment has awrite-read-write configuration, which may use shortened closures thatthus allow closer gap-to-gap separation.

Additional aspects of the embodiments shown in FIGS. 6 and 7 are similarto those given above.

A 32 channel version of a multi-module head 126 may use cables 350having leads on the same or smaller pitch as current 16 channelpiggyback LTO modules, or alternatively the connections on the modulemay be organ-keyboarded for a 50% reduction in cable span. Over-under,writing pair unshielded cables may be used for the writers, which mayhave integrated servo readers.

The outer wrap angles α₁ may be set in the drive, such as by guides ofany type known in the art, such as adjustable rollers, slides, etc. oralternatively by outriggers, which are integral to the head. Forexample, rollers having an offset axis may be used to set the wrapangles. The offset axis creates an orbital arc of rotation, allowingprecise alignment of the wrap angle α₁.

To assemble any of the embodiments described above, conventional u-beamassembly can be used. Accordingly, the mass of the resultant head may bemaintained or even reduced relative to heads of previous generations. Inother approaches, the modules may be constructed as a unitary body.Those skilled in the art, armed with the present teachings, willappreciate that other known methods of manufacturing such heads may beadapted for use in constructing such heads. Moreover, unless otherwisespecified, processes and materials of types known in the art may beadapted for use in various embodiments in conformance with the teachingsherein, as would become apparent to one skilled in the art upon readingthe present disclosure.

Servo pattern and data read sensors may experience shorting failuresduring normal data writing and/or reading operations. Particularly, suchshorting may be caused by protruding defects (herein “surface defects”)in the magnetic tape recording media (also generically referred to as“tape”), such as agglomerations of abrasive particles or other defects,e.g., hard particulates, that protrude from the tape surface. Suchsurface defects may smear and/or plow conductive material from the thinfilms of the reader across the sensor, thereby creating an electricalshort.

While this issue is relevant to current-perpendicular-to-plane (CPP)readers in general, this problem is particularly problematic with CPPTMR sensors. Because the deposition thickness of the tunnel barrier theTMR sensor is very thin, e.g., less than about 10 angstroms in someapproaches, smearing of conductive material thereacross is a pervasiveproblem. Accordingly, TMR sensors may be particularly susceptible tosuch shorting due to the thin sensor gap.

Interactions between tape media surface defects and a sensor surface mayalso lead to friction-related functionality issues. For example, when asurface defect passes over a sensor, friction may lead to plasticdeformation of one or more delicate thin films of the sensor. Plasticdeformation of the delicate thin films may alter the stress distributioninside the sensor, and this may be presented as noise due to magneticinstability, e.g., switching magnetic domains.

Narrower write heads may also be subject to degradation via spacing lossresulting from gouges caused by tape surface defects.

Such problematic surface defects may protrude from the surface of thetape, and may include one or more agglomerations of abrasive particles.The surface defects may also include dense agglomerations of bindermaterials.

Such surface defects may result from, e.g., the milling of particlesused in the tape, e.g., where a large particle is added to the tapemedia during manufacture; a manufacturing defect during any knownmanufacturing process, such as creation of an agglomerate of wearparticles or binder that protrudes from the media; etc.

Embodiments described herein include implementing a tough, dense,preferably ceramic block with at least one skiving edge positioned alonga tape bearing surface thereof in order to mitigate, e.g., viaburnishing, tape media defect abrasivity and/or eliminate defect(s) of atape media altogether.

The block may have one or more skiving edges along a tape bearingsurface thereof. Each skiving edge may burnish surface defects in thetape media surface along the tape bearing surface. While a few, looseagglomerations may be broken free during the process, burnishing of thesurface defects generally entails reducing the extent of protrusion ofthe defect.

In a preferred embodiment, the block, or at least the skiving edge ofthe block, may have a hardness that is at least equal to the hardness ofthe surface defects in the tape media surface. This ensures that theblock is not easily worn away and/or broken in response to coming intocontact with a surface defects in the tape media surface.

According to one embodiment, the block may have an average hardness ofat least about 9 Mohs. However, the average hardness of the block mayvary depending on the embodiment.

According to one embodiment, the block, and most notably the skivingedge(s) of the block, may be preferably harder than the material(s),e.g., that make up the surface defects that may be included in the tape.For example, the block having an average hardness of at least about 9Mohs would make the block harder than a surface defect of the tape thatincluded barium ferrite and/or alumina particles.

The hardness of different portions of the block may vary depending onthe embodiment. For example, the hardness of the skiving edge may bedifferent than the hardness of a portion of the block that does notcontact surface defects in the tape media surface along the tape bearingsurface.

According to another example, the block may include more than one layerof deposited block material. According to one approach, the hardness oftwo or more layers of a block that includes more than one layer ofdeposited block material may be the same, and/or the hardness of two ormore layers of the block may be different.

In embodiments where the block includes more than one layer of depositedblock material and/or in embodiments where the block includes one blockmaterial, the block may be cut and/or polished to desired dimensions.The block may be cut and/or polished to desired dimensions using, e.g.,standard ceramics processing, a laser, a diamond or carbide blade, etc.

The block may include one or more materials selected from the followinggroup: aluminum oxide-titanium-carbide (AlTiC), silicon carbide,sapphire, diamond, titanium carbide, boron nitride, zirconium oxide andtitanium nitride. The block may also and/or alternatively include one ormore other materials that would be appreciated by one skilled in the artupon reading the present description.

The block may be mounted on a tape head assembly, such as head assembly200 of FIG. 2, in a tape drive system, such as tape drive system of FIG.1A.

According to various embodiments, the block may replace a tape head orportion thereof, such as the head in the drive of FIG. 1A. In oneapproach, the head may be completely replaced with one or more blocks.In another approach, the head may be a hybrid system that includes ablock and an active head on a single module.

For purposes of an example, referring now to FIG. 8, a pair of blocksare mounted in a simulated head assembly, as will now be described. FIG.8 depicts a simulated head assembly 800, in accordance with oneembodiment. As an option, the present simulated head assembly 800 may beimplemented in conjunction with features from any other embodimentlisted herein, such as those described with reference to the other FIGS.Of course, however, such simulated head assembly 800 and otherspresented herein may be used in various applications and/or inpermutations which may or may not be specifically described in theillustrative embodiments listed herein. Further, the simulated headassembly 800 presented herein may be used in any desired environment.

The simulated head assembly 800 includes a first block 802 and a secondblock 804. The first block 802 and the second block 804 have “u-beam”shaped profiles, but the profile of the blocks 802, 804 and/or otherblocks described elsewhere herein should not be interpretively limitedthereto.

For example, in one or more different embodiments, the blocks 802, 804may have, e.g., rectangle profiles, curved profiles, square profiles,etc.

The block 802, 804 may also include any suitable dimensions, and shouldbe wider than the width of the tape media. Other dimensions may varydepending on the embodiment. For example, the dimensions of a block mayvary depending on, e.g., the dimensions of the tape of the drive inwhich the block is implemented, the spatial constraints of a drive inwhich the block is implemented, the intended mobility of the block, etc.

According to one non-limiting approach, the skiving edge(s) and/or theblock(s) may have a width, e.g., that is measured along an axis 816, ofat least 22.5 mm, e.g., to span the entire surface of the tape thatcontacts the block.

According to another non-limiting approach, the blocks 802, 804 may havedimensions which include a 22.5 mm width, a 2.75 mm length (measured inthe direction 814), and a 1.75 mm height.

The first block 802 may include a first skiving edge 806 and,optionally, a second skiving edge 808. Similarly the second block 804may include a first skiving edge 812 and, optionally, a second skivingedge 810. The skiving edges 806, 808, 810, 812 may be configured toburnish surface defects in a magnetic recording tape along a tapebearing surface.

Configuring the skiving edges 806, 808, 810, 812 of the blocks 802, 804to burnish surface defects in a magnetic recording tape along a tapebearing surface may include, e.g., angling the skiving edges 806, 808,810, 812 with respect to a wrap angle of a tape approaching the skivingedge, spacing the blocks 802, 804 apart a determined distance, varyingthe average hardness and/or block material of the blocks 802, 804, etc.as will be described in greater detail elsewhere herein.

The orientation of the skiving edges 806, 808, 810, 812 relative to aparticular tape travel direction may be selected based on, e.g., thedirection of tape travel, the speed in which the magnetic recording tapeis traveling, the material of the blocks 802, 804 and/or the averagehardness of the blocks 802, 804, etc.

According to one embodiment where the tape bearing surfaces of theblocks 802, 804 lie along parallel planes, as magnetic recording tape ispassed over the blocks 802, 804 in the direction 814, the first skivingedge 806 of the first block burnishes surface defects in the magneticrecording tape. Similarly, as magnetic recording tape is passed over theblocks 802, 804 in a direction substantially opposite direction 814, thefirst skiving edge 812 of the second block 804 burnishes surface defectsin the magnetic recording tape.

According to a preferred embodiment, where the tape bearing surfaces ofblocks 802, 804 are angled in an overwrap configuration, e.g., similarto the tape bearing surfaces shown in FIG. 2, as magnetic recording tapeis passed over the blocks 802, 804 in the direction 814 shown in FIG. 8,the first skiving edge 806 of the first block 802 and the second skivingedge 810 of the second block 804 burnishes surface defects in themagnetic recording tape. Similarly, as magnetic recording tape is passedover the blocks 802, 804 in a direction substantially opposite direction814, the second skiving edge 808 of the first block 802 and the firstskiving edge 812 of the second block 804 burnishes surface defects inthe magnetic recording tape. In a similar manner, more than two blocksmay be used to provide even more burnishing effect.

In some approaches, using multiple skiving edges to simultaneouslyburnish a tape, the wrap angle associated with each skiving edge may bedifferent. Each configuration may provide a differing burnishing effect,which may be useful in dealing with different types of asperities on agiven tape. For example, a shallower wrap angle may be more effective atburnishing some types of asperities, while a higher wrap angle may bemore effective at burnishing other types of asperities. Moreover, suchvarying wrap angles may be further used in combination with blocks ofdiffering material types to provide a burnishing system that iseffective across a wider range of asperities and/or tape media types.For example, monolithic brittle asperities are more likely to beburnished by the higher shear forces associated with a high wrap angle,whereas agglomerations may be effectively burnished at shallower wrapangles which exert less overall stress on the tape.

The skiving edges 806, 808, 810, 812, located along outer edges of thetape bearing surfaces of the blocks 802, 804, may have substantiallyninety degree profiles. The configurations of the skiving edges 806,808, 810, 812 may vary depending on the embodiment.

It should be noted that the burnishing of surface defects of a tape mayinclude passing the portions of tape that include surface defects overthe skiving edges of the blocks any number of times. For example,according to one embodiment, a burnishing sequence may include passing aportion of tape that includes surface defects over a block one time.According to a different embodiment, a burnishing sequence includespassing a portion of tape that includes surface defects over a blockmore than one time, e.g., two times, three times, four times, etc.

A guide mechanism such as guides in FIG. 1A may be configured to set awrap angle of a tape approaching the skiving edge of the block. Theguide mechanism may include, e.g., tape guides such as guides 125 ofFIG. 1A, pitch rollers, a tension arm, etc.

The wrap angle may be set, e.g., by the guide mechanism, to any anglethat promotes the burnishing of surface defects off the tape mediasurface. According to one embodiment, the wrap angle may be at least onedegree. According to preferred embodiments, the wrap angle may be in arange of about two to about three degrees.

In general, a wrap angle high than one degree is greater than would beused for conventional read/write operations because the high wrap angleresults in higher friction, which is beneficial for burnishing but isnot only unnecessary for read/write operations, but excessive frictioncan lead to deleterious velocity variations of the tape.

The wrap angle may preferably angle the tape media for burnishing ratherthan removing defects that protrude from the tape surface. Setting awrap angle for burnishing rather than removing the defects that protrudefrom the tape surface may prevent undesirable craters from forming inthe tape media, e.g., as a result of an entire agglomeration of defectmaterial being ripped out of the tape media surface. Moreover, removalof such agglomerations may create debris within the drive, which canlead to other problems.

Performing a burnishing rather than removal of surface defects may beespecially advantageous for tape media(s) that includes “iceberg”profile defects. An iceberg profile surface defect may have a protrudingportion that extends out of the surface of the tape, as well as a largerunderlying portion that is embedded in the magnetic layer and/orunderlayer of a magnetic recording tape. According to one embodiment,the underlying portion of an iceberg profile surface defect of a tapemay extend, for example, 750-1250 nm into a tape in the thicknessdirection and have a similar diameter as measured along the plane of thetape.

It should be noted that the described iceberg profile of a surfacedefect has been introduced for descriptive purposes only, and should notbe interpreted to limit the descriptions of surface defects (describedherein) which the block may burnish. The iceberg profile of a surfacedefect also provides an example of a defect that would likely create anundesirable crater in the tape if removed, rather than burnished by oneor more of the blocks described herein.

A drive mechanism such as a motor or other known mechanism may beconfigured to cause the tape to move over the block. For example, themotor or other known mechanism may drive a tape supply cartridge, e.g.,tape supply cartridge 120 of FIG. 1A, and a take-up reel, e.g., take-upreel 121 also of FIG. 1A, of a drive in which the block is implementedin, to move the tape media over the block and/or other components of thedrive.

The drive mechanism may cause the tape to move over the block at anyspeeds that promote burnishing of surface defects off the tape surface.

According to preferred embodiments, the drive mechanism may cause thetape to move over the block at speeds that do not reduce normalthroughput of the tape drive. For example, during read operations, thedrive mechanism may cause the tape to move over the block at speeds thatare normal during read and/or seek operations.

Preferably, the tape tension is maintained at about a constant levelwhen moving the tape over the block. The about constant tape tension mayprovide a consistent degree of burnishing across the tape media that ispassed over and burnished by the block.

In a further embodiment, tape jitter and/or lateral translation of theblock relative to the tape may be introduced during a burnishingoperation. For example, one or both motors may be manipulated tointroduce tape jitter, whereby pulses or the like are introduced via themotors. Lateral translation of the block may be accomplished in a mannersimilar to actuation of a conventional head during registering the headsuch as across the various data bands on tape, track following, etc. Thelateral translation may be a continuous back and forth motion, performedin steps, combinations thereof, etc. Lateral translation may helpprevent formation of scarring on the block.

In some embodiments, the block may have no transducer coupled directlythereto, i.e., that is affixed to or movable with the block.

The block may be implemented in a tape drive apparatus that may or maynot have a data head. For example, the tape drive may be aburnishing-only drive.

In further embodiments, the block may be coupled to an active componenthaving active transducers whereby the block and active componenttogether form a single module or larger head. For example, referringagain to FIG. 8, one of the blocks may instead be an active component.This configuration is particularly useful for operations such as servoverification, whereby such apparatus burnishes a tape and verifies theservo tracks. Preferably, the block is detachable from the activecomponent.

In other embodiments, a block may be incorporated into a drive that isalso capable of reading and/or writing data. In some approaches, theblock may be selectively positioned, e.g., in an engaged position, in aretracted position, in a position where the block is accessible by acleaning device, etc., as will now be described below, e.g., see FIGS.9-11C.

FIGS. 9-12 depict simplified tape drives 900, 1000, 1100, 1200 of atape-based data storage system, in accordance with multiple embodiments.As an option, the present tape drives 900, 1000, 1100, 1200 may beimplemented in conjunction with features from any other embodimentlisted herein, such as those described with reference to the other FIGS.Of course, however, such tape drives 900, 1000, 1100, 1200 and otherspresented herein may be used in various applications and/or inpermutations which may or may not be specifically described in theillustrative embodiments listed herein. Further, the tape drives 900,1000, 1100, 1200 presented herein may be used in any desiredenvironment.

It should be noted that the tape drives 900, 1000, 1100, 1200 may have asimilar configuration and/or one or more similar components to that ofthe drive 100 of FIG. 1A. Accordingly, the tape drives 900, 1000, 1100,1200 and the drive 100 may share common numbering.

Referring now to FIG. 9, tape drive 900 includes a block 902. The block902 may include one or more blocks, and/or one or more skiving edges,e.g., for burnishing surface defects of the tape 122. The block 902 oftape drive 900 may be positioned in contact with the tape 122, as shownin FIG. 9.

The tape drive 900 may include a cleaning device 904 such as a brush forautomated cleaning of the block 902 without removal of the block 902from the tape drive 900. Automated cleaning of the block 902 withoutremoval of the block 902 from the tape drive 900 may include thecleaning device 904 brushing any loose materials, e.g., that result fromthe burnishing of the tape, from the block surface and/or any areasaround the skiving edge(s) of the block, e.g., such as the gap betweenthe blocks 802, 804 of FIG. 8.

The cleaning of the block 902 is preferably performed during afunctional downtime, e.g., while a tape 122 is not being advanced acrossthe block and/or when the block is retracted from the tape path.

According to different embodiments, the cleaning device 904 mayalternatively and/or additionally include, e.g., a brush, a fan, a pick,a vacuum, etc.

The cleaning device may also be positionable to clean the block 902 whenthe block 902 is in a retracted position, e.g., see FIG. 11A.

The tape drive 900 may include a tape head 126 with at least onetransducer. The configuration of the tape head 126 may vary depending onthe embodiment, as described elsewhere herein.

Although the block 902 is shown not coupled to an actuator, such asactuator 132 that may be coupled to the tape head 126, the block 902and/or any of the blocks described herein may be coupled to an actuator,e.g., see FIG. 10.

Referring now to FIG. 10, the tape drive 1000 includes the block 902.The block 902 may be coupled to an actuator 1002. An actuator 1002 maycontrol the position of the block 902 relative to the tape 122. Forexample, the actuator 1002 may adjust the position of the block 902relative to the tape 122 to change the wrap angle of the tapeapproaching the skiving edge of the block.

The block 902 may be positionable between a burnishing position, e.g.,see FIGS. 10, 11B, for engaging the tape 122 and a retracted position,e.g., see FIG. 11A, whereby the skiving edge of the block 902 is not incontact with the tape 122 in the retracted position.

Referring now to FIG. 11A, the tape drive 1100 includes the block 902which is coupled to the actuator 1002. The block 902 is shown positionedin the retracted position whereby the skiving edge of the block 902 isnot in contact with the tape 122.

The block 902 may be positioned in the retracted position in response toburnishing of the tape 122 being undesirable. For example, the block 902may be positioned in the retracted position in response to, e.g., aninstruction from the controller or a host, a trigger condition beingmet, a user toggling a drive switch, a burnishing already beingperformed on a portion of tape 122 that is advancing over the block 902,etc.

In contrast, referring now to FIG. 11B, the block 902 is shownpositioned in the burnishing position. The block 902 may be positionedin the burnishing position in response to burnishing of the tape 122being desired. For example, the block 902 may be positioned in theburnishing position in response to, e.g., an instruction from thecontroller or a host, a trigger condition being met, a user request, adetection that a portion of tape 122 that is advancing past the block902 includes surface defects, etc. Thus, in some approaches, burnishingmay be performed on demand. Note that the head 126 may be retracted fromthe tape path, if desired, to avoid head wear during the burnishingoperation.

According to a different example, the block 902 may be positioned in theburnishing position in response to a tape being added or removed fromthe drive 1100.

The block 902 may be moved from the retracted position into theburnishing position and/or alternatively from the burnishing positioninto the retracted position by extending arms 1102. The extending arms1102 may be coupled to the actuator 1002 and/or the block 902.Equivalent embodiments may implement a worm screw, a linear actuator,etc.

The block 902 may also be positioned to selectively lift the tape 122from the head 126. For example, referring now to FIG. 11C, the actuator1002 may position the block 902 past the burnishing position of FIG.11B, to selectively lift the tape 122 from the head 126.

The block 902 may be positioned to selectively lift the tape 122 fromthe head 126 for a variety of reasons, such as burnishing the tape;lifting the tape from the head during a high speed tape advancement,e.g., seek operation; decoupling a tape stuck to the head 126 from thehead due to stiction; lifting the tape from the head during idle time toprevent stiction, etc.

Lifting the tape 122 from the head 126 during burnishing of the tape 122may allow for relatively faster rates of burnishing the tape, e.g., inresponse to the tape 122 being advanced across the block 902 at speedsthat exceed discernable read rates. However, the tape may alternativelybe burnished at any slower rate, e.g., a discernable read rate, a slowerthan a discernable read rate, etc. when the tape 122 is lifted from thehead 126.

Referring now to tape drive 1200 of FIG. 12, a servo of the tape 122 maybe verified after the burnishing. The verification may be performed inresponse to a read of one or more servo tracks of the tape 122 beingperformed by one or more components the head 126.

Servo pattern verification may be performed concurrently with burnishingin a cascading manner. For example, a first tape may be burnished. Afterburnishing, the tape may be moved to a servo pattern verification drivewhere the servo pattern is verified. Concurrently, a second tape may beburnished in the drive that just finished burnishing the first tape.Where each tape is to be burnished more than once, a tape may progressthrough a series of burnishing drives, followed by a final drive thatperforms the servo pattern verification process. By performingburnishing and servo pattern verification on multiple tapes in parallel,total throughput can be greatly increased.

According to one approach, verification of one or more servo tracks ofthe tape 122 may include a processor and/or any logic of a controller ofthe tape drive 1200 verifying a readback signal derived by servo readersof a head reading the servo tracks of the tape. Verifying one or moreservos of the tape 122 after burnishing the tape 122 may be performed asa verification measure, e.g., to ensure that one or more of the servotracks of the tape 122 have not been altered during the burnishing.

In response to detecting one or more altered or otherwise defectiveservo tracks of the tape 122 during the verifying by one or more servopattern readers after burnishing, the affected servo tracks may berepaired and/or rewritten. According to one embodiment, the wrap angleof the tape 122 may be adjusted in response to detecting altered servotracks, e.g., where the alteration is determined to result fromburnishing of the tape 122.

With continued reference to the tape drive 1200, the tape 122 may bepassed over a skiving edge of a second block 1202 at a wrap angle of atleast one degree having the block 902, thereby further burnishing thetape 122. Thus, the effect of multiple burnishing operations may beprovided in fewer passes.

In an alternate embodiment, two drive apparatuses may be used to performsequential burnishing operations. For example, after burnishing the tapein one drive using a first block, the tape may be transferred to asecond drive that is different than the first drive and passed over askiving edge of a second block at a wrap angle of at least one degree inthe second apparatus.

Burnishing surface defects from the surface of the tape 122 using morethan one block, e.g., blocks 902, 1202, may refine the burnishingperformed on the tape 122.

For example, burnishing surface defects from the surface of the tape 122where the first block 902 has one or more aggressive skiving edge(s),e.g., where the skiving edges burnish the tape 122 at a wrap anglesubstantially greater than one degree, and the second block 1202 has oneor more non-aggressive skiving edge(s), e.g., where the skiving edgesburnish the tape 122 at a wrap angle substantially close to one degree,or alternatively vice versa, may promote a consistent burnishing of thetape 122, regardless of the size of the surface defect being burnished.

Using more than one block when burnishing surface defects of the tape122, e.g., blocks 902, 1202, may also reduce the degree of wear that theskiving edges of each of the more than one blocks experience from theburnishing.

It should be noted that blocks that experience wear as a result of theburnishing may be easily replaced and/or repaired. In order to easilyreplace the blocks in the drives described herein, the blocks maypreferably be configured to be easily detached from the drive in whichthey are implemented. For example, the blocks may be attached in thedrives using one or more, e.g., clips, screws, clamps, etc. Repairs maybe made by machining along the skiving edge(s).

The tape drive 1200 may also include an actuator 1204 that controls theposition of the second block 1202 relative to the tape 122.

Similar to the first block 902, the second block 1202 may bepositionable between a retracted position and a burnishing positionand/or alternatively from the burnishing position into the retractedposition by extending arms 1206 or equivalent structure.

The tape drive 1200 may also include a second cleaning device 1208,e.g., for cleaning the second block 1202.

The blocks 902, 1202 of the tape drive 1200 may be configured to burnishdifferent types of surface defects in the tape 122. For example, inaddition and/or alternatively to the potential for the first block 902and the second block 1202 to burnish the tape at different wrap anglesas described elsewhere herein, the blocks 902, 1202 may includedifferent materials, e.g., that are each conducive to burnishingdifferent types of surface defects.

It should be noted that tape drives that include more than one blockshould not be interpretively limited to including a maximum of twoblocks. Rather, tape drives that include more than one block should beinterpreted to be capable of including any practical number ofburnishing blocks, where each of the multiple blocks may be positionedand/or include materials that promote the burnishing of differentsurface defects, e.g., defects that differ in size from one another,defects that differ in material from one another, defects that differ inthe degree to which they are bound in the tape medium, etc.

In a different embodiment the blocks described herein may beincorporated into a simulated head structure which may replace amagnetic head assembly in a tape drive, e.g., drives 100, 900-1200. Onenotable advantage of such an embodiment is that the simulated head maybe cleaned in the same manner as the data head might otherwise be, e.g.,by automatic brushing in the drive.

The burnishing described herein may be performed using acomputer-implemented, e.g., controller-implemented, method. The methodmay include causing the magnetic recording tape to pass over the blockhaving a skiving edge.

In one embodiment, a tape that is to be burnished may be loaded into adrive, and firmware may cause motion of the tape, where the tape maypass over the simulated head structure (block), preferably at constanttension and speed. The cartridge housing the tape may be loaded by anautoloader, before and/or after one or more burnishing operations, mayautomatically be loaded into a servo verification drive. In such anembodiment, as described elsewhere herein, the tape may approach theskiving edge at a wrap angle of at least one degree for burnishing thetape.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Moreover, a system according to various embodiments may include aprocessor and logic integrated with and/or executable by the processor,the logic being configured to perform one or more of the process stepsrecited herein. By integrated with, what is meant is that the processorhas logic embedded therewith as hardware logic, such as an applicationspecific integrated circuit (ASIC), a field programmable gate array(FPGA), etc. By executable by the processor, what is meant is that thelogic is hardware logic; software logic such as firmware, part of anoperating system, part of an application program; etc., or somecombination of hardware and software logic that is accessible by theprocessor and configured to cause the processor to perform somefunctionality upon execution by the processor. Software logic may bestored on local and/or remote memory of any memory type, as known in theart. Any processor known in the art may be used, such as a softwareprocessor module and/or a hardware processor such as an ASIC, a FPGA, acentral processing unit (CPU), an integrated circuit (IC), etc.

It will be clear that the various features of the foregoing systemsand/or methodologies may be combined in any way, creating a plurality ofcombinations from the descriptions presented above.

It will be further appreciated that embodiments of the present inventionmay be provided in the form of a service deployed on behalf of acustomer.

The inventive concepts disclosed herein have been presented by way ofexample to illustrate the myriad features thereof in a plurality ofillustrative scenarios, embodiments, and/or implementations. It shouldbe appreciated that the concepts generally disclosed are to beconsidered as modular, and may be implemented in any combination,permutation, or synthesis thereof. In addition, any modification,alteration, or equivalent of the presently disclosed features,functions, and concepts that would be appreciated by a person havingordinary skill in the art upon reading the instant descriptions shouldalso be considered within the scope of this disclosure.

While various embodiments have been described above, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of an embodiment of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims and their equivalents.

What is claimed is:
 1. An apparatus, comprising: a block having multipleskiving edges along a tape bearing surface thereof; a guide mechanismconfigured to set a wrap angle of a tape approaching the skiving edge;and a drive mechanism configured to cause the tape to move over theblock, wherein the block has no transducer coupled directly thereto. 2.An apparatus as recited in claim 1, wherein the wrap angle is at leastone degree.
 3. An apparatus as recited in claim 1, wherein the block hasan average hardness of at least about 9 Mohs.
 4. An apparatus as recitedin claim 1, wherein the block comprises at least one material selectedfrom a group consisting of: AlTiC, silicon carbide, sapphire, diamond,titanium carbide, boron nitride, zirconium oxide and titanium nitride.5. An apparatus as recited in claim 1, wherein the drive mechanism isconfigured to maintain about a constant tape tension when moving thetape over the block.
 6. An apparatus as recited in claim 1, comprising acleaning device for cleaning the block without removal of the block fromthe apparatus.
 7. An apparatus as recited in claim 1, wherein the blockis positionable between a burnishing position for engaging the tape anda retracted position whereby the skiving edge of the block is not incontact with the tape.
 8. An apparatus as recited in claim 1, comprisinga head with at least one transducer.
 9. An apparatus as recited in claim8, wherein the block is positioned to selectively lift the tape from thehead.
 10. A computer-implemented method, comprising: causing a magneticrecording tape to pass over a block having a skiving edge at a wrapangle of at least one degree for burnishing the tape, wherein the blockhas an average hardness of at least about 9 Mohs.
 11. A method asrecited in claim 10, wherein the block comprises at least one of siliconcarbide, sapphire, diamond, titanium carbide, boron nitride, zirconiumoxide and titanium nitride.
 12. A method as recited in claim 10,comprising maintaining about a constant tape tension when moving thetape over the block.
 13. A method as recited in claim 10, comprisingcausing cleaning of the block without removal of the block.
 14. A methodas recited in claim 10, comprising causing the block to move between aburnishing position for engaging the tape and a retracted positionwhereby the skiving edge of the block is not in contact with the tape.15. A method as recited in claim 10, comprising causing the block tolift the tape from a head having at least one transducer.
 16. A methodas recited in claim 10, comprising verifying a servo pattern of the tapeafter the burnishing.
 17. A method as recited in claim 16, wherein theburnishing of the tape is performed by a first apparatus and theverifying of the servo pattern of the tape is performed by a secondapparatus, and further comprising burnishing a second tape using thefirst apparatus simultaneously with the verifying using the secondapparatus.
 18. A method as recited in claim 17, comprising burnishing athird tape in a third apparatus concurrently with the verifying of theservo pattern of the tape using the second apparatus and the burnishingof the second tape using the first apparatus.
 19. A method as recited inclaim 10, comprising, after burnishing the tape, causing the tape topass over a skiving edge of a second block at a wrap angle of at leastone degree in a second apparatus different than a first apparatus havingthe block, thereby further burnishing the tape.
 20. A computer programproduct for burnishing a magnetic recording tape, the computer programproduct comprising a computer readable storage medium having programinstructions embodied therewith, wherein the computer readable storagemedium is not a transitory signal per se, the program instructionsexecutable by a processing circuit to cause the processing circuit toperform a method comprising: causing a magnetic recording tape to passover a block having a skiving edge at a wrap angle of at least onedegree for burnishing the tape, wherein the block has an averagehardness of at least about 9 Mohs.